The present invention relates to detectors for use in detecting moisture in potting media for plants. Moisture detectors of this type are well known and several different types are available. Some operate by detecting changes in the electrical resistance or capacitance of the soil near a plant as the level of moisture changes, and indicate, with lights or in other ways, that the level of moisture is inadequate. The user then knows to water the plant.
Furthermore, novelty moisture detectors are also well known. These include detectors with bodies in the form of frogs or other creatures.
Batteries or solar cells connected to rechargeable batteries may be used to power these detectors. It is important to know when the batteries are no longer delivering sufficient voltage to operate the detector. A detector with a dead battery gives the same signal as one indicating sufficient moisture, even when the soil is dry.
Thus, there remains a need for improvements in moisture detectors, regardless of type, that inform the user that the battery power is low.